Unless otherwise indicated herein, the description in this section is not itself prior art to the claims and is not admitted to be prior art by inclusion in this section.
Various types of medical devices provide relief for recipients with different types of sensorineural loss. For instance, hearing prostheses provide recipients with different types of hearing loss with the ability to perceive sound. Hearing loss may be conductive, sensorineural, or some combination of both conductive and sensorineural. Conductive hearing loss typically results from a dysfunction in any of the mechanisms that ordinarily conduct sound waves through the outer ear, the eardrum, or the bones of the middle ear. Sensorineural hearing loss typically results from a dysfunction in the inner ear, including the cochlea where sound vibrations are converted into neural stimulation signals, or any other part of the ear, auditory nerve, or brain that may process the neural stimulation signals.
Persons with some forms of conductive hearing loss may benefit from hearing prostheses with a mechanical modality, such as acoustic hearing aids or vibration-based hearing devices. An acoustic hearing aid typically includes a small microphone to detect sound, an amplifier to amplify certain portions of the detected sound, and a small speaker to transmit the amplified sounds into a recipient's ear via air conduction. Vibration-based hearing devices typically include a small microphone to detect sound, and a vibration mechanism to apply vibrations corresponding to the detected sound to a recipient's bone, thereby causing vibrations in the recipient's inner ear, thus bypassing the recipient's auditory canal and middle ear via bone conduction. Types of vibration-based hearing aids include bone anchored hearing aids and other vibration-based devices. A bone-anchored hearing aid typically utilizes a surgically implanted abutment to transmit sound via direct vibrations of the skull. Non-surgical vibration-based hearing devices may use similar vibration mechanisms to transmit sound via direct vibration of teeth or other cranial or facial bones. Still other types of hearing prostheses with a mechanical modality include direct acoustic cochlear stimulation devices, which typically utilize a surgically implanted mechanism to transmit sound via vibrations corresponding to sound waves to directly generate fluid motion in a recipient's inner ear. Such devices also bypass the recipient's auditory canal and middle ear. Middle ear devices, another type of hearing prosthesis with a mechanical modality, directly couple to and move the ossicular chain within the middle ear of the recipient thereby bypassing the recipient's auditory canal to cause vibrations in the recipient's inner ear.
Persons with certain forms of sensorineural hearing loss may benefit from cochlear implants and/or auditory brainstem implants. For example, cochlear implants can provide a recipient having sensorineural hearing loss with the ability to perceive sound by stimulating the recipient's auditory nerve via an array of electrodes implanted in the recipient's cochlea. An external or internal component of the cochlear implant comprising a small microphone detects sound waves, which are converted into a series of electrical stimulation signals delivered to the cochlear implant recipient's cochlea via the array of electrodes. Auditory brainstem implants use technology similar to cochlear implants, but instead of applying electrical stimulation to a recipient's cochlea, auditory brainstem implants apply electrical stimulation directly to a recipient's brain stem, bypassing the cochlea altogether. Electrically stimulating auditory nerves in a cochlea with a cochlear implant or electrically stimulating a brainstem can help persons with sensorineural hearing loss to perceive sound.
A typical hearing prosthesis system that provides electrical stimulation (such as a cochlear implant system, or an auditory brainstem implant system) comprises an implanted sub-system and an external (outside the body) sub-system. The implanted sub-system typically contains a radio frequency coil, with a magnet at its center. The external sub-system also typically contains a radio frequency coil, with a magnet at its center. The attraction between the two magnets keeps the implanted and external coils aligned (allowing communication between the implanted and external sub-systems), and also retains the external magnet-containing component on the recipient's head.
The effectiveness of any of the above-described prostheses depends not only on the design of the prosthesis itself but also on how well the prosthesis is configured for or “fitted” to a prosthesis recipient. The fitting of the prosthesis, sometimes also referred to as “programming,” creates a set of configuration settings and other data that defines the specific characteristics of how the prosthesis processes external sounds and converts those processed sounds to stimulation signals (mechanical or electrical) that are delivered to the relevant portions of the person's outer ear, middle ear, inner ear, auditory nerve, brain stem, etc.
Hearing prostheses are usually fitted to a prosthesis recipient by an audiologist or other similarly trained medical professional who may use a sophisticated, software-based prosthesis-fitting program to set various hearing prosthesis parameters.